Electric heater



July 31, 1923.

W. A. RANKIN ELECTRIC HEATER Originl Filed April 12 1921 Invenfov: William A.Rankin,

His Attorney Patented July 31, 1923,

UNITED STATES 1,463,630 PATENT OFFICE.

WILLIAM A. RANKIN, OF OAK PARK, ILLINOIS, ASS IGNOR TO EDISON ELECTRIC APPLIANCE (10., INC., A CORPORATION OF NEW YORK.

ELECTRIC HEATER.

Application filed April 12, 1921, Serial No. 460,728. Renewed April 4, 1923.

To all whom it may concern:

Be it known that I, WILLIAM A. RANKIN, a citizen of the United States, residing at Oak Park, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Electric Heaters, of which the following is a specification.

My invention relates to electric heaters and has for its object the provision of means whereby the current supply to the heater is automatically turned on and off to maintain a predetermined average temperature.

More specifically, my. invention relates to thermostatic cut-outs for electric fiat-irons, percolators, and the like. The usual construction of devices of this character has been to arrange the thermostatic element in insulated relation to the heated body; therefore, the element is not readily responsive to the temperature of the heated body.

In carrying out my invention, I employ a thermostatic element which is attached directly to the heated body so that the temperature of the body is transmitted quickly to the thermostatic element which is therefore immediately responsive thereto.

In the accompanying drawing, Fig. 1 is a perspective view of an electric iron equipped in accordance with my invention; while Fig. 2 is a diagrammatic view of the heating circuit.

Referring to the drawing, on the fiat-iron body 10 of the cast in heating unit type is mounted a thermostatic plate 11 in a recess 12 in the body of the fiat-iron. The thermostatic plate is held rigidly in place at one end in intimate heat conducting relation with the body of the flat-iron by screws 13 and 14 passing therethrough.

The screw 14 also holds in place one end of bar 15 made of electrically conducting material, the other end of which is held in place by a screw 16. The bar 15 is insulated from the flat-iron and held in spaced relation thereto by means of suitable insulators carried by screws 14 and 16.

An insulated contact 17 is carried by the end of the thermostatic plate and cooperating therewith is a contact 18 carried by bar 15. The terminal 19 of the heating element of the flat-iron is electrically connected by strap 21 to bar 15. A conductin strip 22 is attached by means of a fiexib e branch portion 23 to the contact 17. Another branch 24 of strip 22 is connecte be t rmi nal 26 of a condenser 25 mounted on the flat-iron, the other terminal 27 of which is connected to bar 16. The strip 22 and branch strips 2 3 and 24 are supported in insulated relation to the flat-iron and to the thermostatic plate, or suitable insulation may be provided between these members. In order'to allow for free lateral movement of the thermostatic plate, the strip 23 is extended along the thermostatic plate and connected to strip 22 at a point adjacent the point of support of the plate. For a like reason the recess 12 is graduall deepened toward the free end of the t ermostatic plate. v

The heating unit 28 is provided with a. suitable insulating jacket] and cast in the body of the flat-iron, terminals 19 and 20 being brought out for connection to a source of electric supply. A suitable protecting cap or casing having the usual handle will be attached to the flat-iron over the condenser and current carrying parts.

During the operation of the heater, a source of electric supply is connected .to terminal 20 and strip 22 through a suitable form of plug connection or otherwise. Con-i tact 17 is normally held by the thermostatic plate firmly against contact 18 so that current is supplied to theresistanceelement 28 through the contacts. of the heated body increases the thermostatic plate is affected until at some predetermined maximum temperature the distortion of the free portion of the thermostatic plate in a downward direction will be sufficient to,

move contact 17 away from contact 18 thus opening the heating circuit. The flat-iron now cools until a predetermined minimum temperature is reached when the heating circuit is again closed by the thermostat through contacts 17 and 18. The condenser 25 connected across the contacts 17 and 18 is provided to prevent arcing between 'the contacts and consequent burning thereof.

In accordance with the provisions of the patent statutes, IL have described the principle of operation of my invention, to ther with the apparatus which I now consi er to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

What I claim as new and desire to secure As the temperature by Letters Patent of the United States, is:

1. The combination with an electric heater, of a body heated thereby, a thermostaTtic "element attached to said body in direct heat conducting relation therewith, and cooperatinginsulatedcontacts in the circuit of said heater, one of which is carried by said thermostatic element, whereby the temperature of said body is controlled by the thermostatic element.

2. The combination with an electric heater, of a body heated thereby, a thermostatic plate attached to said body in direct heat conducting relation therewith, a stationary insulated contact, and a movable.insulated contact carried by said thermostatic plate normally cooperating with said stationary contact, said contacts being connected in the circuit of said heater, whereby the temperature of said body is controlled by the thermostatic late.

3. The com ination with an electric lieat er, of a body heated thereby, a thermostatic plate attached to said body in direct heat conducting relation therewith, a stationary insulated contact connected in the circuit of said heater, a movable insulated contact carried by said thermostatic plate normally cooperating with said stationary contact, and insulated means extending along said thermostatic plate for connecting said movable contact in the circuit of said heater, Whereby the temperature of said body is controlled by the thermostatic plate.

4. The combination with an electric heat er, of a body heated thereby, a recess in said body, a thermostatic element in said recess in direct heat conducting relation to saidbody and adapted to be heated by conduction therefrom, and means controlled by said thermostatic element for controlling said heater.

.5.- The combination w'th an electric heater of a body heated thereby, a relatively short thermostatic element having relatively large area in direct heat conductin relation to said body, and means controlle by said thermostatic element for controlling said heater. p

'6. The combination with" an electric heater of a body heated thereby, a recess in sa1dbody, a thermostatic plate supported in Said recess in directheat conducting relation to said body, and contacts in the circuit of said heater one of which is carried by said thermostatic element, whereby thetemperature of said body is controlled by the thermostatic late.

7. The combination with an electric heater, oi a body heated thereby, a recess in said body, a thermostatic plate supported in said recess in direct heat conducting rela- "tion to said body, a stationary insulated the circuit of said heater, a movable insulat-- ed contact carried by the other end of said thermostatic plate normally cooperating with said stationary contact, an insulated flexible conducting; strip extending along said thermostatic plate for connecting said movable contact in the circuit of said heater, and a condenser connected across said contacts, whereby the temperature of said body is controlled by said thermostatic plate.

in Witness whereof, I have hereuntoset my hand this 2th day of April, 1921.

a... Martin. 

